It is known that display quality of liquid crystal display device significantly varies with a temperature of the device. This is attributed to the fact that liquid crystal properties (such as response speed) which influence display quality, have a certain temperature dependency.
Accordingly, some liquid crystal display devices have been proposed, in which the temperature of liquid crystal display device, in particular the temperature of display panel or liquid crystal itself is measured, so that improvement of the display quality can be carried out based on the measurement.
Patent Literature 1 discloses a liquid crystal display device comprising a liquid crystal cell having substrates facing each other with counter electrodes, and liquid crystal is sealed between the substrates, wherein a temperature compensation sensor including a polysilicon resistive element is provided in the liquid crystal cell. This liquid crystal display device allows an easy configuration of a circuit for temperature compensation.
Patent Literature 2 discloses a liquid crystal display device using a temperature sensor for measuring temperature based on an oscillating frequency of a ring oscillator, which is made of the same material as TFT for drive circuit and produced concurrently by the process for producing the TFT. With this liquid crystal display device, display defect resulting from a temperature change of liquid crystal panel can be solved thereby attaining high quality display property.
Patent Literature 3 discloses a liquid crystal display device comprising a liquid crystal display panel having such a structure that a liquid crystal material is sandwiched between a first substrate and a second substrate, wherein a manufacturing process of a first semiconductor element for driving a liquid crystal pixel formed on the first substrate is utilized to produce a second semiconductor element for detecting the temperature of the liquid crystal material in the liquid crystal display panel. This liquid crystal display device requires no cost increase to achieve accurate temperature measurement during operation of liquid crystal material and accurate control of liquid crystal drive voltage based on the temperature measurement.
Patent Literature 4 discloses a liquid crystal display device comprising temperature detecting means for directly detecting the temperature of the liquid crystal inserted in a liquid crystal display pixel to output a detection signal and driving control means for controlling the period of inverted signal polarity of display signal voltage applied to the liquid crystal display pixel based on the detection signal. This liquid crystal display device achieves low power consumption, together with the display image quality in which occurrences of flickers are reduced.
Patent Literature 1
    Japanese Unexamined Patent Publication No. 34519/1992 (Tokukaihei No. 04-34519) (Publication Date: Feb. 5, 1992)Patent Literature 2    Japanese Unexamined Patent Publication No. 2000-9547 (Tokukai No. 2000-9547) (Publication Date: Jan. 14, 2000)Patent Literature 3    Japanese Unexamined Patent Publication No. 2000-338518 (Tokukai No. 2000-338518) (Publication Date: Dec. 8, 2000)Patent Literature 4    Japanese Unexamined Patent Publication No. 2004-226470 (Tokukai No. 2004-226470) (Publication Date: Aug. 12, 2004)